The following instruments are no longer available for science use. Their web pages will be available indefinitely, to support data processing and analysis of distributed and archived data, but may not be updated.

CIRPASS (near-IR Integral Field Unit spectrograph) was offered as a visiting instrument, loaned by the University of Cambridge, during 2002-2003.

Flamingos-I (near-IR imager and multi-object spectrometer) was offered as a visiting instrument, loaned by the University of Florida, on Gemini South.

Hokupa'a-36 / QUIRC (natural guide star adaptive optics system and its near-IR camera) was offered as a visiting instrument, loaned by the University of Hawaii for early science on Gemini North. It is has since been replaced by the facility AO system Altair.

NIRSPEC (near-IR spectrograph on Keck) was offered to the Gemini community for limited use during 2000-2001.

OSCIR (mid-IR imager/spectrometer) was offered as a visiting instrument, loaned by the University of Florida for early science on Gemini North and, more recently, on Gemini South. It was replaced by the facility mid-IR instruments Michelle and T-ReCS.

The Gemini Observatory is an international collaboration with two identical 8-meter telescopes. The Frederick C. Gillett Gemini Telescope is located on Mauna Kea, Hawai'i (Gemini North) and the other telescope on Cerro Pachón in central Chile (Gemini South); together the twin telescopes provide full coverage over both hemispheres of the sky. The telescopes incorporate technologies that allow large, relatively thin mirrors, under active control, to collect and focus both visible and infrared radiation from space.

The Gemini Observatory provides the astronomical communities in five participant countries with state-of-the-art astronomical facilities that allocate observing time in proportion to each country's contribution. In addition to financial support, each country also contributes significant scientific and technical resources. The national research agencies that form the Gemini partnership include: the US National Science Foundation (NSF), the Canadian National Research Council (NRC), the Chilean Comisión Nacional de Investigación Cientifica y Tecnológica (CONICYT), the Brazilian Ministério da Ciência, the Argentinean Ministerio de Ciencia, Tecnología e Innovación Productiva, Tecnologia e Inovação and the Korea Astronomy and Space Institute (KASI). The observatory is managed by the Association of Universities for Research in Astronomy, Inc. (AURA) under a cooperative agreement with the NSF. The NSF also serves as the executive agency for the international partnership.